Notes from the field – Cloud Design Part 1

I’ve had an interesting last couple of weeks having discussions with customers who are both already in the public cloud and those that are dipping a toe. One recurrent theme seems to be the idea of taking what you have on premises and putting it into the cloud and expecting it to work in exactly the same way.

I’ve been working with cloud technologies for coming up on 5 years now, and in that time, this concept has been prevalent all the way through. There is a famous quote that seems to have been attributed to different historical people, including Einstein and Henry Ford, but instead I’m going to use Aerosmith’s interpretation of it:-

Cause if you do what you’ve always done
you’ll always get what you always got
Uh could that be nothin’

Steven Tyler, Aerosmith “Get A Grip”

Now that I’ve shoe horned in a hard rock reference, let’s look at what that actually means. For a start, many larger organisations use the end of a DC lease to trigger their move into public cloud by doing a “lift and shift” of VMs into the cloud, maybe deploying a couple of third party appliances (such as CloudGuard IaaS, of course) and then declaring themselves “in the cloud”. Job done.

Well yes and no.

Let me be clear on my view that if you are moving to cloud to save money, you’re doing it for entirely the wrong reasons. Really what you’re buying into is hyperscale technologies – the ability to provision highly complex stacks with a few clicks of a button and paying only for what you use.

If you drag and drop a bunch of most probably oversized VMs into cloud, when you get the monthly bill, you’re in for a shock. In my experience, compute charges make up the lion’s share of your bill. Do your research ahead of time and look if there are ways you can mitigate this cost.

For starters, if you have simple web serving needs, why not use the ability to publish web sites via S3 buckets, or maybe an Azure Web App? There are multiple tiers in the latter service, depending on what levels of performance and resilience you want.

If you have bursty compute requirements, look at auto scaling technologies or even serverless. Don’t be sucked into the dogma that serverless cures all ills, because it doesn’t. Used in the right way, it can be highly cost effective and elegant. Used in the wrong way, it can be expensive and inflexible for your needs.

dogma
noun [ C or U ] disapproving
UK /ˈdɒɡ.mə/ US /ˈdɑːɡ.mə/

a fixed, especially religious, belief or set of beliefs that people are expected to accept without any doubts

Cambridge Dictionary

Not to say there isn’t anything wrong with lift and shift of VMs into Azure, AWS, GCP, etc. But it’s a staging post, it’s not a destination. One public sector body I worked with a couple of years ago were really switched on to this. They saw L&S as very much a phase one, then used the “long tail” method of transitioning their apps to something more cloud native, using technologies such as Azure SQL and Azure Web Apps.

As usual, this post is a bit more of a brain dump than anything more formal. In future posts I intend to explore some more of the experiences I’ve had in the field and hopefully some will resonate with you.

As always, comments welcome. You can reach me on Twitter @ChrisBeckett.